Evolution of flowering time due to variation in the onset of pollen dispersal among individuals.

This article focuses on the evolution of flowering time in plant populations driven by variation in individual siring success due to differences in the onset of pollen dispersal, independent of temporal variation in pollination rates. Using quantitative genetic models and evolutionary game theory, it demonstrates that mean flowering time tends to evolve earlier when pollen removal rates are low, pollen deposition rates are high, and the fertilization ability of removed pollen declines slowly, while the evolutionarily stable variance in flowering time is influenced by pollen removal and deposition rates and pollen viability decline. The study also models the coevolution of flowering time and flower longevity, finding that under constant pollination rates, late flowering correlates with longer flower longevity due to nonrandom mating, suggesting that observed correlations between late flowering and shorter flower longevity in nature arise from other factors such as declining pollination rates or individual quality. The findings highlight the complex effects of altered pollination dynamics, including those induced by climate change, on flowering time evolution and emphasize the importance of distinguishing between pollen removal and deposition rates in empirical research.